Jonathan Silver, administrator of the U.S. Department of Energy’s loan guarantee program, is resigning from his post. Until now, Silver was the head of the DOE’s Loan Programs office. That office oversaw the program that gave now-bankrupt Solyndra its $535 million loan guarantee. The transaction left taxpayers on the hook when the company failed. Though President Barack Obama continues to tout solar energy as a boon for the future, Silver’s resignation may signal that key Obama administration officials lack confidence in a strategy of subsidizing loan guarantees for companies in hat Obama calls the “green jobs” economy.